MM58274C National, MM58274C Datasheet
MM58274C
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MM58274C Summary of contents
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... This device is pin compatible with the MM58174A but continues timekeep- ing up to tens of years The MM58274C is a direct replace- ment for the MM58274 offering improved Bus access cycle times ...
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... Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications DC Input or Output Voltage Input or Output Diode Current Storage Temperature STG Supply Voltage V DD Power Dissipation P ...
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AC Switching Characteristics READ TIMING DATA FROM PERIPHERAL TO MICROPROCESSOR V Symbol Parameter t Address Bus Valid to Data Valid AD t Chip Select On to Data Valid CSD t Read Strobe On to Data Valid RD t Read Strobe ...
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... Switching Time Waveforms Connection Diagrams Dual-In-Line Package Top View Order Number MM58274CJ MM58274CN or MM58274CV Read Cycle Timing (Notes 5 and 7) Write Cycle Timing (Notes 5 and 11219–4 FIGURE 2 See NS Package J16A N16A or V20A 11219 – 11219 – 3 PCC Package TL F 11219 – ...
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... Functional Description The MM58274C is a bus oriented microprocessor real time clock It has the same pin-out as the MM58174A while offer- ing extended timekeeping up to units and tens of years To enhance the device further a number of other features have been added including hours counting a testable ...
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Functional Description (Continued) device which are synchronously clocked by this signal All time data and data-changed flag change on the falling edge of the clock setting pulse Data-Changed Flag The data-changed flag is set by the clock setting pulse to ...
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Functional Description (Continued) Day of Week Counter The day of week counter increments as the time rolls from ( 12-hour mode) It counts from and ...
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... The read only portion of the control register has two status outputs Since the MM58274C keeps real time the time data changes asynchronously with the processor and this may occur while the processor is reading time data out of the ...
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... METHODS OF DEVICE OPERATION Test Mode National Semiconductor uses test mode for functionally testing the MM58274C after fabrication and again after packaging Test mode can also be used to set up the oscil- lator frequency when the part is first commissioned Figure 4 shows the internal clock connections when the de- ...
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... Characteristics should be examined As long as these tim- ings are met (or exceeded) the MM58274C will function cor- rectly When the MM58274C is connected to the system via a pe- ripheral port the freedom from timing constraints allows for very simple control signal generation as in Figure 7 For ...
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... Functional Description (Continued) FIGURE 5 MM58274C Microprocessor Interface Diagram FIGURE 6 Valid MM58274C Control Signals Using Chip Select Generated Access Strobes TL F 11219 – 11219 – 8 ...
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Functional Description (Continued) a Port Generated Read Access 2 Addresses Read Out b Port Generated Write Access 2 Addresses Written To FIGURE 7 Simple Port Generated Control Signals 11219 – 11219 – 11 ...
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... TV VCR clocks any system where real time is displayed The interrupt timer on the MM58274C can generate inter- rupts synchronously with the time registers changing using software to provide the initial synchronization In single interrupt mode the processor is responsible for ini- ...
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... Physical Dimensions inches (millimeters) Cavity Dual-In-Line Package (J) Order Number MM58274CJ NS Package Number J16A Molded Dual-In-Line Package (N) Order Number MM58274CN NS Package Number N16A 15 ...
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... National does not assume any responsibility for use of any circuitry described no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications Plastic Chip Carrier (V) Order Number MM58274CV NS Package Number V20A 2 A critical component is any component of a life ...